When more current from a digital output is needed than a single output could source or drain, a digital amplifier can be used. In this case, the gates as inverters can be connected in a parallel manner to increase the devices capabilities. The circuit shown here is an example of digital amplifier and buffer that uses four gates of a 4093 IC or any other IC that can be connected as an inverter [4001, 4011, 4048, etc]. Six inverters of a 40108 can also be used in the same configuration. Another use for digital buffers is providing isolation between stages. The maximum input frequency for this circuit depends on the power-supply voltage and is 10 MHz with a power supply of 10 V.
Digital Amplifier
